Fast path planning for robot manipulators using numerical potential fields in the configuration space

We present a path planning algorithm for robot manipulators working in an initially known environment. An efficient method constructs the configuration space (C-space) of the robot and expands a local-minima-free numerical potential field in it. So the robot is able to move very fast and collision-free within its workspace (W-space). An extension of that principle allows the robot to handle autonomously new obstacles appearing in its W-space in a fast manner. We have implemented the planner on our 6 degrees of freedom (DOF)-considering 5 of them-space robot ROTEX working within a tight workcell. In order to reduce the off-line computation time of the C-space, the C-space may be only partially constructed taking approximately 5 minutes on a Silicon Graphics IRIS Indigo R4000. Pathfinding solutions for many practical situations are then produced in less than 1 minute